Apparatus for drawing sheet glass



Sep. 7 192e. LSQSJYM H. G. SLJNGLUFF APPARATUS FOR DRAWING SHEET GLIASSFiled Feb. 25, 1923 :s sheets-sheet 2 'iN WE N TR giga/Mgg Sept 7 1926H. (El. SMNGLUFF APPARATUS FOR DRAWING SHEET GbASS Filed Feb. 25, 1923 3Sheets-Sheet 41 wie Patented Sept. 7, 1926.

- UNITED. STATES PATENT MERY G. SLIGLUFF, F MOUNT VERNN, OHIO, ASSIGNRTO miaieil-i GLASS COM'PANY, A CORPORATION OF PENNSYLVANFCA.

APPARATUS FOR DRAWING SHEET GLASS.

Application filed February 26, 1923. Serial No. 621,184.

The invention relates to apparatus for drawingr glass in a continuoussheet. It has for its primary objects the provision ofan improvedapparat-us, (l) which will draw the glass sheet continuously withoutimpos ing any substantial strain thereon tendine,r to break it, (2)which can be installed in a limited amount of overhead space, (3) whichshall be ofrelatively cheap simple Iconstruction with a low cost ofupkeep, (4;) which keeps the glass sheet relatively flat and straight,and which provides for a v reduction in temperature of the glass sheetduring the drawing operation lsuch that breakage `is avoided, and theglass is so annealed and reduced in temperature that it may be cut otand handled Without difliculiy as it emerges from the upper end of theapparatus. One embodiment et the invention is shown in the accompanyingdrawings wherein:

Figure 1 is an end elevation of the apparatus. Fig. 2 is a frontelevation Wit-h the curtain or belt on the near side removed in order toshow certain of the parts which would otherwise be covered. Fig. 3 is aplan View. Fig. 4 is a detail view of a small section of one of thecurtains or belts showing the reinforced construction ot the fabricandlig. 5 is a perspective detail view.-

The drawing apparatus to which the pres' ent invention relates is shownas located above the tank construction preferably eni- 'ployed, but isnot limited to use with such shielding members 8 and 9 lying above thebath on opposite sides of the sheet.

The main drawing'torce tor the sheet 1s 'applied by means of the endlessbelts or 17, each of which is embedded in the asasbestos protects theWires from the action ot the heat and provides a relatively soitfiexiblerefractory surface tor contacting with the Iglass. The drawing; rolls l2and 13 and 14 and 15 are also covered with a similar fabric of Whichthere may be several layers, thus giving a yielding contact with theglass sheet and avoiding any scratching or marring which might otherwisebe present with rolls having metai contacting surfaces.

The belts 10 and 1l are driven from the pulleys 18 and 19 at the upperends of the apparatus and tension is applied to the belts at their lowerends by means ot the steel bars 20 and 21 'placed in the lower endsthereo't.

These. bars 2O and 21 are circular in cross section and aresupported'entirely by the belts. The pulleys 18 and i9 are preferablyspaced apart as indicated in Fig'. i so that no pressure is applied'bysuch rolls to the glass sheet 5 which passes therebetween. in this Wayany tendency to break the glass is avoided Which might otherwise occurif the glass as itpassed these pulleys was not perfectly flat. l

The pulleys 18 and 19 are driven from a pair of counter shafts 22 and 23which counter'shafts. carry at the ends the sprockets 24 and 25 gearedto correspondin a` sprockets 26 and 27 on the ends` oit the pul leyshafts by means of the sprocket chains 28 and 29. The opposite ends otthe courr ter shafts-22 and 23 are provided 'with in termeshing' spur2gears 30 and 31 (Fig. 3). the shaft 23 also being;1 provided witha'spur gear 32 which is driven 'from the electric motor 83 by means otthe reducing" rearing shown in Figs. 2 and This reducing' gearingincludes a worm drive in the casing 34, spur gears 35 and 56 and thespur gear 37 onthe shaft ot the Worm Wheel.

Rollers 12 and 13 and 'leiand l5 are driven from counter shaltts A38 and39 and such counter shai'ts are driven from the counter shafts 22 and23by means et sprocket Wheels 42 and t3 on the shafts and 23 and aroundsprockets 44e and e5 on the shafts 38 and 39. Each of the shafts 38 and39 carries a pair of additional sprocket Wheels 46 and 47 which drivethe sprockets 48 and 4:9 on. the shafts of the -site sides ofthe glasssheet.

rollers 12, 13, 14 and 15, this being accomplished by means of suitablesprocket chains 50 and 51.

The upper drawing rolls 14 and 15 are carried upon bell crank hangers,the vertiv cal legs 52 of which hangers carry the rolls at their lowerends, while-the horizontal arms 53 of such hangers are 'provided withcounter weights 54 sb that the rolls 1l and 15 are pressed inwardlyagainst the oppo- The drawing rolls 1Q and 13 are similarly supportedand pressed inward by means of the bell crank levers 55. The horizontalarms of these levers are not shown in Fig. 1, as they he behind the arms53, but they are similarly arranged and provided with suitable counterweights; Both sets of bell crank hangers are pivotally supported uponthe shafts 38- and 39. L

In order to provide for the support of the apparatus, vertical frameworkis preferably employed consisting of the angle irons 55 suitably tiedtogether and `carried by the brackets 57 mpunted upon the horizontalangles 58 which are secured to the superstructure of the building inwhich the apparatus is employed. The apparatus is ordinarily of suchlength that a tloor 59 may be provided just above the angles 58, thusgiving convenient access to the upper end of the drawing mechanism.

In order to cause the belts to engage the glass sheet with properdrawing force and distribute the` strain over -the area. of the belts, aseries of rolls are provided between the flights of each belt and soarranged as to yieldingly press against the surfaces of the belts, suchrolls being arranged opposite ,each other so that the pressure of4 oneis counterbalancedby another lying opposite and any tendency to breakthe glass through uneven pressure is avoided, A considerable part ofthis gripping pressure is applied from the idler rolls -6l) located )ustbelow the belt driving rolls 18 .and 19 and supported upon the counterweighted bell crank hangers 61, such hangers being pivotedA at 62 to theframework angles 56. These rolls are preferably .covered with asbestosand extend across the width of the drawing belts. Located beneath therolls are other bell crankhangers 63 pivoted at 64; (see Figs. 1 and 5)`to the frame angles 56 and supporting the transverse bars 65. These bars65 are provided with pairs of arms 66 between each of which is a rela-.of-the drawing belt.

ferent elevations so as to better distribute' the pressure of the seriesof rolls :over the belt and over the lass which op oses the belt. Theserolls 6 exert relativelgf only a `-life several IVimes over.

slight plesure upon the belts since they are hung free y upon the bars65 and' press up on the belt-only by reason o f thafaet that the centerofthe 'bar 65 lies, slightly-closer ported from the bars 72, 73, 74: and75, as'

above described in connection with the roll- 'ers (57, such'bars beingcarried upon the bell crank hangers 7G, 77, 78 and 79. In this manneryieldingr pressure is applied to the vbacks of the belts at a largenumber of separate points so that the strain upon the glass and thedrawing strain' upon the belts is distributed. This also serves thepurpose of keeping the belts well in contact with the glass so lthat thecooling of the glass will be more uniform than if the belts had anopportunity to move out of Contact with the glass over considerableareas. The cool ing of the glass is thus made more uniform and thetendency to breakage due to unevenness in cooling is reduced.

Ii'nn'icdiatcly below the drawing rolls 12 and 13 are located a pair ofwater coolers and 81 extending transversely of the apparatus andincreasing in diametcnfrom their ends to their centers. are cooled by acirculation of water from the inlet Si). to the outlet 83 and their useassists in increasing the speed of draw, Since they exert a certainamount of chilling effeet upon the glass bath and also upon the glasssheet, which is plastic for a short distance upward from the surface ofthe glass. This chilling e'ect may be regulated by moving the coolerstoward and from the sheet and also toward and from the sur` face of theglass. The members are varied in diameter from their` ends to the centerin order to give a variable cooling efi'ect upon the glass, the tendencyof the center ofthe. sheet normally .being to run hotter thanl Avtheedges and vtending to draw thinner than `the edges.' The use of thewater-,coolers tends to counterzutthis'tendency and gives a sheet inwhich the thickness is more uniform so that it is less liable to break.also perform an important function in connection with. the rolls 12 and13. These rolls, as before stated, are covered with an asbestos fabricand this fabric rapidly deteriora-tes under intense heat. 'llierolls arenecessarily placed closel to the glass bath These members The coolers 1and subject to great heat. The use of the water cooled members beneaththe rolls protects them from this heat and increases their In a similar'way, the-sets of rolls 12 and 13 protect the rolls levend 15 and theyin turn protect the belts 10 and 11., l In this way, the use ofthedrawing devices beneath the belts involves a great saving in upkeep, asthe life of the belts 'is quantity of material involved is very muchgreater than 'that of the drawing rolls be-` neath.

In case of breakage of the glass between the belts, it is often possibleto continue the drawing operation because ot the use of the rolls 12 andlS-and 14 and 15. The pressure exerted by these `ro1ls is sufiicient tocontinue the pullingv of the glass even when the break extends to apoint beneath the curtains. The

"rolls also steady the glass sheet and tend to maintain it in its Eroperposition with reue to inequalities' in the temperature ofthe glass bath,there isA a certain tendency at times for' the sheet to move so that,its line of generation is oi center with respect to the center line ofthe guide bar 3, andin such case,` the drawing rolls apply a constantpressure tending to correct this condition and bring the sheet to itsproper position. They also protect the sheet from the heat of the bathbeneath so that the glass enters the belts at a lower teinperature thanwould otherwise be the case. As a result the sheet passes through'andleaves the belts at a lower temperature than would otherwise be thecase, rendering it easier to cut and handle. The temperature conditionsare such that the glass is practically annealed before it enters thebelts having a temperature ranging from 500 to 700 F. The conductingquality of the belts is such that the glass drops `trom thisternperature to approximately 150o to 250 F. in its passage to the upperend of the apparatus, at which point it is cut ofi. This rate of coolingis slow enough to prevent any substantial breakage and yet sutiicientlyrapid to permit of proper handling and cut ting of the glass upon itsemergence from, the curtains. This relatively rapid cooling is due tothe fact that the belts are composed of a relatively thin woven texturewith nothing to prevent the dispersion of heat from the rear faces of'the belt tiights in contact with the glass.

The dimensions of the apparatus and its location with respect to thebath will vary depending upon conditions, but in drawing at from 20 to30 inches per minute, the lower ends of the -belts may be located about4 feet from the surface ot the glass and that the belts are of suchlength that their upper ends are about 13 feet from the surface of 87.The shafht 86 is provided with a suitable rotating mechanism (not shown)so that by turning on this shaft the lever 85 may be moved upward. thusmoving all ot' the counterweighted arms upward and suing-ing' therollers 67, 68, 69, and 7l outward away from the cfirtain so that suchcurtain may move to the `rear.

The cooling of the glass in its passage through the belts or curtains ispromoted by the use of the air pipes 88, one ot' which is shown inFig.`2. These pipes are placed just to the rear of the inner [lights ot'the belts and have a series of perfor-ations directed toward thecurtain. Air is supplied from a fan or other suitable source,`and servesto reduce the temperature of lthe curtains and the glass passingtherebetween. The cooling renders the glass' easier to handle and cut.

What I claim is:

l. In combination, apparatus tor drawing glass in sheet form'continuously from a bath ot' molten glass, comprising a pair of opposingvertical endless driven belts, means for causing the belts to grip theglass sheetJ being drawn therebetween, a pair of opposing rollspositioned intermediate the bath of v weights for causing the rolls toyieldinglyl press against the glass sheet in opposition l to each other.

3. Incombination, apparatusfor drawing glass sheet' form continuously.from a bath of molten glass, comprisingl pair of opposing verticalendless driven be s, means for causing the belts to grip the glass sheetbeing drawn therebetween, a pair of opposing rolls positionedintermediate the bath oi glass and the lower ends of said belts andmounted for swinging movement toward and from the glass sheet,counterweights for causing the rolls toi yieldingly press against theglass sheet in opposition to each other and means for driving saidrolls.

a. in combination, apparatus for drawing glass in sheet formcontinuously rom a bath of molten glass, comprising a pair of opposingvertical endless driven belts,

means for causing the belts to grip the glass l sheet being drawntherebetween, a plurality of pairs of opposing. drawing rolls po-'sitioned intermediate the bath of glass and the lower ends of saidbelts, means for cansn 13 ing the rolls to press vinward yieldinglyagainst the surfaces of the-glass sheet, and means for drivin the rolls.

5. In combination, apparatus for drawing glass in sheet form,continuously from a bath. oimolten glass, comprising a pair of opposingendless belts, pulleys 'over which the belts passat their uppel e1i ds,tension bars supported' free to movejvertically in the lower ends of thebelts, arid means inter" mediate said pulleys and'saill bars forapplyingiyielding pressure to the rear faces of the inner lights of thebelts to causey them to grip the gliss sheet-being drawn therebetween. l

6. In combination, apparatus for drawing glass in sheet formcontinuously from a bath oi`- molten glass, comprising a pair nl A.

of opposing endless belts,l pulleys over which the belts pass at theirupper ends, tension weights in the form of circular bars lying in thelower ends of the belts, and means intermediate said pulleys and saidbars for applying yieldingT pressure to the rear faces of the innei`flights of the belts to cause them to grip the glass sheet being drawntherebetween. 7. In combination, apparatus for drawing glass in sheetform continuously from a bath of molten glass, comprising a pair ofopposing endless beltsypulleys over which the belts pass at their upperends, tension bars supported free to move vertically in the' lower endsof the belts, and of less diameter than said pulleys and spaced apart soas to provide a V shaped entrance opening between tbe lower ends of thebelts, and means intermediate said pulleys and said bars forv applyingyielding pressure to the rear faces of the inner -flights of the beltsto cause them to grip the glass sheet being drawn therebetween.

. 8. In combination, apparatus for drawin glass in sheet formcontinuously from a bath of molten glass, comprising a pair of opposingendless driven belts, means for causing the belts to grip the glasslsheet be-A ing drawn therebetween, a pair of opposing` driven rollscovered' with asbestos fabric and positioned intermediate' the bath ofglass and the lower ends of said belt-s, means for causing the rolls topress inward against the surface of the glass sheet, and protectin watercooled conduits .extending longitu inally below the rolls and adjacentthereto.

9. In'combination, apparatus fordrawing glass in sheet formcontinuously' from a bath of molten glass comprising a pair of opposingendless belts of flexible asbestos fabric having metallic wirereinforcing woven therein, means for, driving the belts, mea-ns forapplying pressure Vto the belts to cause themto grip the glass, andmeans for applying air blasts 'to the rear ,faces of the `flights of thebelts in contact with the glass to coolthe belts and the glasstherebetween.

IO. In glass drawing apparatus ordrawing a sheet or ribbon continuuslyfrom a bath `oi molten glass, a pair of vertical op posing endlessinsulating curtains spaced above the bath adapted to receive the sheetand contact with it while the glass is dropping in temperature from thatbelow the settmg point to a point at which the glass may be crackedoil', and opposing driven 'rollers between the ,(iurtains andthe glassfor applying drawing force to the sheet.

ll. In glass dra iing apparatus for drawing a sheet or ri boncontinuously from a bath o finolten glass, a pairof vertical opposingendless insulating curtains spaced above the bath `/adapted to receivethe sheet and contact with itwhile the glass is dropping in temperatureroni'tliat below the setting point to a point at which the glass may becrackedhpl and a plurality of pairs of opposing driven l-rollers betweenthe curtains and the glass bath for applying draw- -i'ng force to thesheet.

12. In combination in apparatus for HARRY G. sLiNGLUFF.

